Folklore attributes to seawater a variety of healing powers. It is possible that the high salt concentration and resulting high osmolality of seawater contributes to whatever healing power seawater might have. Medical science has yet to confirm or refute healing powers attributable to seawater.
Many prior art methods have been proposed for the treatment of various animal body tissues with solutions containing sodium chloride and other ingredients. One such method involves treating skin and scalp conditions with a saline solution. The solution is prepared by evaporating seawater by heat, subjecting the concentrated liquid obtained to a low temperature to separate by crystallization a part of the magnesium sulphate and a part of the sodium and potassium chlorides, drawing off the liquor from the precipitate, redissolving the magnesium sulphate and adding the liquor with a small amount of acetic acid to the solution. Another method involves forming a saline solution by dissolving zinc sulphate and sodium chloride in water and applying it as an eyewash or lotion. Still another method relates to the use of salts of an alkali-forming metal containing small amounts of available chlorine and even smaller amounts of free alkali as a germicidal solution.
There are currently on the market several pharmaceutical products which mimic the hyperosmolar effect of seawater. A product sold under the name of Debrisan acts as a hypertonic solution; it consists essentially of hydrophilic beads of dextranomer, which, it is claimed, sucks fluid and bacteria out of wounds. The small beads are poured directly onto the wound, and, of course, must be washed out periodically.
There are, however, various disadvantages associated with application of seawater and other similar hypertonic solutions to sensitive and/or inflamed tissue. Hypertonic solutions shrink normal tissue, and will, for example, irritate mucosal tissue such as that found in the eye, nose, throat, vagina, etc. Hypertonic solutions are also known to desensitize a variety of bacteria that might otherwise be susceptible to antibiotic therapy. Many antibiotics are effective in that they damage bacterial membranes thus inhibiting reproduction of the bacteria. Hypertonic solutions may serve to stabilize bacterial membranes, thus blunting the effect of such antibiotics.